1. Field of the Invention
The present invention relates to a liquid discharge head, and in particular, to an ink jet recording head which generates recording liquid droplets for use in an ink jet recording system.
2. Description of the Related Art
As an application in which a liquid discharge head is used, there is known an ink jet recording head which is applied to an ink jet recording system. The ink jet recording head generally includes fine ink discharge ports (hereinafter, referred to as “orifices”), liquid flow paths, and liquid ejection energy generating elements arranged in the liquid flow paths. As a method of manufacturing such an ink jet recording head, U.S. Pat. No. 5,478,606 and U.S. Pat. No. 6,390,606 discuss a method including the following steps.
First, an ink flow path pattern made of a soluble resin is formed on a substrate on which energy generating elements are formed. Next, a coating resin layer including an epoxy resin and a photopolymerization initiator is formed on the ink flow path pattern. The coating resin layer constitutes an ink flow path wall. Next, orifices are formed above the energy generating elements by photolithography. Finally, the soluble resin is removed by dissolution and the coating resin layer which constitutes the ink flow path wall is cured, to thereby form the ink flow path.
In recent years, with the development of a recording technology, highly precise and high-speed recording has been demanded in an ink jet recording technology. As a method which meets highly precise and high-speed recording, investigations of a method of minimizing and densely forming the orifices so as to minimize ink droplets ejected from the ink jet recording head are advanced. In particular, if the orifices are minimized, a member for forming the ink flow path wall is swollen by absorbing water. Accordingly, the area of each orifice may be changed. The change of the area of the orifice may affect printing. In addition, if the orifices are densely formed, that is, if the width of the ink flow path wall is decreased, the close contactness between the member for forming the ink flow path wall and the substrate may be deteriorated due to being swollen. That is, for the sake of minimizing and densely forming the orifices of the ink jet recording head, there is a need for a technology which can suppress ink absorption of the member for forming the ink flow path wall.